Means for cutting windows in well casings



IA4 c. slNcLAlR 2,216,963

MEANS FOR CUTTING WINDOWS IN WELL CASINGS Oct. s, 1940.

2 Sheets-Sheet l Filed OG..A 9, i959 Oct. 8, 1940.' A. c. slNLAm M ENANS FOR CUTTING WINDOWS IN WELL CSINGS 2 Sheets-Sheet 2 FN\\\\\\\\\\ n n w l E N N v. x. 7|||1 Mlll w v k f Q. n elif u Patented Oct. 8, 1940 IUNITED STATES MEANS Fon CUTTING wINDows 1N WELL casinos Alfred C'. Sinclair, Houston, Tex., assignor to Joseph E. Sinclair, Houston, Tex.

Application october 9, 1939, serial No. 298,717

4 Claims. (Cl. Z55-1) This invention relates to new and useful im' provements in means for cutting windows in well casings. I a f In modern well drilling operations, the Vwell hole often becomes clogged or blocked for some reason. This may be due to tools that have been lost in the wellhole and cannot be shed out, or it may be due to tubing that has become stuck in the well hole and cannot be loosened. In cases such as these, it is desirable to start a new or branch hole oi from the old hole at an angle arid slightly `above the blockedportion, so that said blocked portion is avoided, and at the same time as much as possible of the old, or previously drilled, well hole is utilized. There are also certain other cases in which it is desirable to drill a wellV hole at an angle or to drill a new hole off at an angle from the old hole.

Previously, it has been the practice to use al whipstock to guide-the drill bit in cutting through the casing and starting the'new hole. In many instances the-drill bit or mill used for this 0peration "cut the face of the whipstock, while said whipstock was engaged in guiding said mill, to such an extent that the process was rendered tedious and unreliable." Also, as soon as a portion Vof the casing window was cut, the mill was no longer held against. eccentric and random movements. Such eccentric movements of the mill caused considerable damage to the casing and the new hole being started. V

One object, therefore, of this invention is to provide improved means for cutting windows in wellcasings, wherein the cutting mill is guided in its cutting path and prevented from .eccentric or random movements, whereby the casing and the newly started hole are protected against damage from such movements.

Another'object f this invention is to provide means for cutting windows in well casings, wherein the cutting mill is guided in its path and cuts or mills out the guiding means as said mill passes downwardly.

A further object of this invention is to provide improved means for cutting windows in well casings, wherein the cutting mill is provided Withvention will beV hereinafter described, together with other features'of the invention.

The invention will be morereadily understood from a reading of the following specification and by reference to the accompanying drawings, in which an example of the invention is shown, and wherein:

, 5 Figure l isa view, partly in section and partly in elevation, showing a construction for carrying out the invention,

Figure 2 is a similar view showing the finishing cutter engaging the casing wall,

10 Figure 3 is a horizontal cross-sectional view taken on the line 3-3 of Figure 1,

Figure 4 is a similar view taken on the line Il-d of Figure 1,

Figure 5 is also a similar view taken on the line 5 5 of Figure 2,

Figure 6 is a vertical, sectional View showing a modied form of the invention,

Figure 7 is a similar view showing the same form, the window being partially cut in the casing wall,

Figure 8 is a horizontal cross-sectional viewl` taken on the line 8-8 of Figure 6,

Figure 9 is a similar view taken on the line 9-9 of Figure 7, and

Figure 10 is a horizontal cross-sectional view takenon the line IIl--IIJ of Figure '7. r Irrthe drawings the numeral I0 designates a well casing sych as is mounted within well bores and through which it is desired to cut a side window. As in all casing strings, the lengths of casing I 0 are joined by coupling collars II, and a -suitable whipstock body or mandrel I2 is mounted Within said casing. It is vpointed out that any desirable means may be used tosecure the mandrel within the casing, and that the means shown yin Figure 1 is illustrative only. In cutting a side window through a casing, it is preferable not to drill through a coupling collar because the extra thickness of the metal in the collar would only make the cutting job more diilicult. Therefore, the anchoring means for the mandrel is so d'e' signed as to be actuated by a coupling collar in ysuch a manner that the latter is avoided, and not alowed to fall in the path to be cut.

As shown in Figure 1, the mandrel fits snugly within the bore of casing I0, and is held securely in this position by setting means I3 located in the circular bottom portion thereof. 'I'he setting,r means I3 includes a downwardly'tapered surface I4`\located at one side and near the bottom of the mandrel I2. Suitable casing .engaging slips I5 are mounted on the surface I4 and rest upon the left-hand end of a lever arm I6. The lever arm I6 is pivotably mounted within a. transverse horizontal groove I 1 in the bottom of the mandrel by means of a pin I8, and is free to swing in a. vertical plane. The right-hand end of lever arm I6 carries a pin I9 by which said arm is connected to the lower end of an actuating iinger 20. The nger 20 is disposed within a vertical groove 2I cut in the side of the mandrel, and'has its upper end 22 curving outwardly toward the inside wall of the casing I0. After the mandrel has beenl lowered into the well hole, the subsequent raising of said mandrel will cause the upper end 22 of finger 20 to engage in the joint formed by a coupling collar, as shown in Figure 1.

Manlfestly, upon further upward movement of the mandrel, the finger Will be held against movement, and thereby swing the lever arm I6, and cause slips I5 to move upwardly. As the slips move upwardly, they are forced, by the taper of surface I4, into engagement with the inside wall of casing Ill. sure on the mandrel will serve only to force the slips into more intimate engagement with the casing, whereby downward movement of the mandrel is prevented. Thus, the mandrel is securely positioned within the well casing.

The upper portion 23 of the mandrel is made in the form of an elongate concavo-convex wedge having an apex 24 and an inclined concaved bearing surface 25. The bearing surface 25 extends downwardly from the apex 24 to the opposite wall of said casing. It is pointed out that the bearing surface may be formed with two or more different slopes or inclines 26 and 21, the slope 21 being of greater pitch and located at the bottom or lower portion of said surface. An elongate web or iin 28 is welded or otherwise fastened to the mandrel in an `axial plane normal to the upper surface 26, and carries a tubular member 29 fastened in the same axial plane along its outer edge. The tubular member 29 may be Welded or otherwise fastened to web 28, as is desired or deemed suitable. The upper end of the tubular member is surrounded with a dished collar 39 which overhangs and is fastened upon the upper edge of the web 28. If desired, the collar may be additionally supported and braced by a short web 32 which is secured to the outside of the tubular member and the under surface of the collar, substantially diametrically opposite the web 23.

The cutting mill .33 is suspended in the well by a tubing string 33 and may be of any desired type, although it is preferable that it have -a frusto-conical bottom or under surface 34, as shown in Figure l. The mill has axial pilot pin 35 projecting from its bottom, and a transverse opening 36 extends through the lower portion of said pin which projects into the upper end of the tubular member 29, being guided thereinto by the collar 30. Similar openings (not shown) are provided in the upper portion of the tubular member in transverse alinement with the opening 36 and a shear pin 31 is passed therethrough. The shear pin is of sufficient strength for the mill to support the mandrel I2 while the assembly is being lowered to the desired point within the well casing, and to permit the mandrel to be set,within the casing by setting means I3, as hereinbefore described. Since the rotation of the tubing 33 and,

the mill 33 will cause the mandrel to rotate, it is possible to position the mandrel within lthe well o Yture'in which an axial finger-on the end of the casing, so that a window may be cut in any desired direction. As pressure is applied to the mill to set the mandrel, and the mandrel is set, the shear pin 31 will be fractured, whereby the ypin 35 will telescope the tubular member and the Subsequent downward pres bottom of the mill will rest upon the collar 30. The device is then ready to cut a window in the casing I0.

As the mill is rotated under pressure, it will cut away collar 39 and commence cutting the tubular member and the webs 32 and 28. Owing to the pilot pin 35, the axis of the mill will be alined with the tubular member 29 as the milling progresses. At the same time it will start cutting the casing wall. The mill will be continually guided in its downward progress by the tubular member, and will be prevented thereby from wobbling and undergoing random movements. The mill 33 will cut down to the position shown in dotted lines in Figure l, at which point it will have cut the tubular member completely away and partially completed the cutting of the window. Whenthe work has been done, the mill 33 and its support are removed from the well hole and replaced by mill 38 shown in Figure 2.

Mill 38, shown in Figure 2, has its cutting surface 39 tapered acutely downwardly to a pointed end 40. The pointed end 40 projects between the remaining uncut wall of the casing and the lower surface 21 of mandrel I2, and is thus supported so as to reduce the wobbling action of the mill, which prevents it from damaging the casing Figures 6 through 10, inclusive. This form of the invention is similar to the iirst form with the exception that the mandrel 50 is substantially circular in cross-section throughout. A longitudinal bore 5I extends through mandrel 50 and inclines from the center of the mandrel at the top,v to one side of the mandrel near its lower end, where said opening emerges from one side wall of said mandrel. A cutting mill 52 similar to mill 33 is used, having an axial pilot pin 53 which Iits within said bore 5I and guides and holds the mill thereby in its cutting path. The upper portion of bore 5I is ared outwardly to form a bowl 54 which serves, as the collar 30, to guide the pilot pin into engagement within bore 5I. In this form of the invention, the cutting the mandrel as well as cut the casing wall. Thus,

4as shown in Figure 7, when the mill has'cut to the lower portion of the mandrel, it has cut a passage through the body of the mandrel as well as cut the casing window. It is pointed out that the mandrel 50 may be connected to the mill 52 by a shear pin (not shown) as in the rst form of the invention, or any other suitable means may be utilized, since the mill may be lowered into the well separately. y'Ihis may be done because the bowl 54 serves to guide pilotl pin 53 into engagement with bore 5I.

It may readily be seen that these two forms of the invention constitute only two of the many structures by which this window cutting operation may be carried out. The invention is not to be limi/ted to these forms, but includes any struccutting mill is engaged by a longitudinal opening and is guidedA therein, whereby said ringer guides the cutting mill in its downward path.

Various changes, alterations Vand modiiications may be made in the size, shape and arrangement of the herein described elements, within the scope of the appended claims.

What Iv claim and desire to secure by Letters Patent is:

1. A casing Window cutting mandrel having an inclined tubular bore, a cutter, and a pilot carried by and depending from the cutter, and having its longitudinal axis in register with Athe longitudinal axis of the cutter, said pilot being of such length and the bore of such diameter so that upon entry of the pilot into i the bore the pilot will effect initial axial alinement of the cutter with respect to the mandrel and upon cutting of the cutter cause angular movement of the cutter, until the cutter axis is substantially at the' same inclination as the bore of the mandrel. Y

2. A casing window cutting device in accordance with claim 1, wherein there is an outwardly and upwardly ilared guiding means at the upper end of the .bore of the mandrel'so as to engage the pilot and guide the latter and thereby the cutter into the bore of the mandrel.

device including a` 3. A casing window cutting device in accordance with claim 1, wherein the mandrel has its upper portion cut-away, wherein there is a tubular mmber which forms the bore of the mandrel, and wherein there is a web-like connection between the periphery of the tubular member and the adjacent wall dening the cut-away portion of the mandrel.

4. A casingywindow cutting device in accordance with claim 1, wherein the mandrel has its upper portion cut-away; wherein the bore Aof the mandrel is formed of a tubular member which has an outwardly flared cup-like member at its upper end; wherein thereis a web-like member connected to the periphery of the tubular member and to the adjacent wall defining the cut-out of the mandrel, and wherein there is a web connected to the underface of the cup-like member and to the periphery ofthe tubular member and which is located substantially opposite to the weblike member. e

ALFRED C.- SINCLAIR. 

